The present invention relates to the field of integrated circuit manufacture; more specifically, it relates to an apparatus and method for directly measuring the clamping force on the edge of a substrate on a tool that applies clamping force pneumatically using a remote pressure regulator.
Many fabrication tools handle the substrate being processed by clamping the edges of the substrate. Generally the clamping force is applied pneumatically using a pressure regulator and gauges that are remotely located from the actual point where the substrate is contacted. Being remote the pressure set by a pressure regulator and indicated on the gauges is not the same as the pressure actually applied to the substrate edge because of friction in the shafts and bearings of the tool and pressure drops in the pneumatic system of the tool making it difficult to accurately calculate the actual force applied by the clamping mechanism. In certain tools, the clamping force can affect the quality and repeatability of the process or result in substrate damage.
Accordingly, there exists a need in the art to mitigate the deficiencies and limitations described hereinabove.